BASF 6106 - Side Select Logic

2.2.8.2 SIDE SELECT LOGrC
The side select logic is used by the double
sided
mini disk drive (BASF 6108) and selects
either head 0 or head 1, depending whether the
SIDE l-signal from the input interface is high
or
low. The side select logic in Fig. 2-29
consists of two head select switches (T 11,
T
12 and associated circuits) and a diode
matrix
(D I, 2, 11, 12, 16, 17). If the SIDE
I-signal is low, transistor T 11 i5 on and
head 0 is selected. The signal COMO/ is at
ground
and generates a forward bias to the
diodes D 11, D
12 and D 16.
In a read operation the read signal induced in
the read/write
coils of head 0 is transferred
trough the diodes D 11, D 12 to the read circuits.
In a write operation the write current generated
in the write
circuits flow5 through these diodes
into the read/write coi15. The erase current is
fed to the erase coil by the diode D 16. At the
same time the diodes D I, D 2 and D 17 are blocked,
because
transistor T 12 is off. Transistor T 12
will be on when srDE 1 is high and head 1 is
activated.
FIRGURE 2 - 29 SIDE SE~ECT LOGrC
2 - 21